Kate Middleton and Prince William have not announced the name of their unborn child nor will they until the baby arrives, according to new reports.

As the Duke and Duchess of Cambridge made another public appearance at a horse race on Friday, guesswork over their child's name swirled.

Nevertheless, the royal couple is not likely to leak any name details ahead of their first child's birth.

"Nobody knows what William and Kate are calling their baby or even if they have decided on a name," a source close to the royals revealed to E! News. "They are being very careful to keep everything to themselves. The duke and duchess are taking their privacy very seriously. They are not speaking to anyone about these private matters."

Although she suffered from acute morning sickness early on, Middleton is said to be "feeling great" now that she is almost six months pregnant.

"She's continuing to feel much better as time goes on," the insider continued, according to E! "Naturally, she's very excited about being a mum."

On Friday, the Duke and Duchess arrived at the prestigious Cheltenham Festival, about 120 miles west of London, where they watched racehorses.

The pregnant duchess donned a camel-colored coat paired with the same Aquatalia brown hat she donned during the wedding in Switzerland last month.

While Kate often opts for relatively inexpensive clothing, the duchess wore cushion-cut citrine diamond earrings by jewelry designer Kiki McDonough to the event, according to People magazine. The earrings cost around $1,800.

Loud cheers and a warm welcome greeted the Duke and Duchess when they arrived. William's aunt, Princess Anne, was also in attendance.

Next week, Middleton is expected to attend a volunteer training event in Cumbria, the Scout Association announced.